I've shot the MM Metalizer clear over all sorts of acrylics, also over and under washes. If I'm getting your message straight you're really spraying over X22 ? And that is over the Alclad. It should work fine in terms of compatability. In my case, whenever I have some idea like this I shoot that specific test though, because you just never know. But I use that clear sealer for a lot of things besides over Metalizer paints. Truth be known i think it's just specifically and well thinned out lacquer. Just sayin.